Prosthodontic and orthodontic apparatus and methods

ABSTRACT

System and method for developing a treatment plan for achieving a treatment goal including creating a virtual model of a dental patient&#39;s dentition; transforming the virtual model of the dentition using virtual prosthodontics to facilitate achievement of the treatment goal; transforming the virtual model of the dentition using virtual orthodontics to facilitate achievement of the treatment goal; iterating on the transforming steps until substantially achieving the treatment goal; and generating an orthodontic treatment plan and a prosthodontic treatment plan based upon the substantially achieved treatment goal.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/189,826, filed Nov. 13, 2018, now U.S. Pat. No. 11,270,033, issuedMar. 8, 2022, which is a continuation of U.S. patent application Ser.No. 15/700,011, filed Sep. 8, 2017, now U.S. Pat. No. 11,227,074, issuedJan. 18, 2022, which is a divisional of U.S. patent application Ser. No.14/461,281, filed Aug. 15, 2014, which is a continuation U.S. patentapplication Ser. No. 12/682,225, filed Mar. 16, 2011, now U.S. Pat. No.8,807,999, issued Aug. 19, 2014, which is a national phase filing, under35 U.S.C. § 371(c), of International Application No. PCT/US2007/081262,filed Oct. 12, 2007, published as WO 2009/048475 on Apr. 16, 2009, thedisclosures of which are incorporated herein by reference in theirentireties.

BACKGROUND

The present invention relates to prosthodontic and orthodontic dentalprocedures.

Orthodontics is a dental specialty concerned with correctingirregularities in a patient's dentition, such as malocclusion.Orthodontics generally involves the realignment and/or repositioning ofa patient's teeth. The corrected alignment and/or position improve thefunction and appearance of the teeth.

Prosthodontics is a dental specialty concerned with correctingirregularities in a patient's dentition, such as missing, misshaped,malformed, or maloccluded teeth. Whereas orthodontics generally involvesrealignment and/or repositioning of a patient's teeth, prosthodonticsgenerally involves reshaping a patient's teeth by grinding or cuttingand/or building up portions of the teeth with biocompatible dentalmaterials. For example, a prosthodontic procedure may involve theplacement of one or more dental restorations, such as crowns, bridges,inlays, and/or veneers. Prosthodontics also corrects for improper toothcolor and shape, which orthodontics alone cannot correct.

SUMMARY

The embodiments of the present prosthodontic and orthodontic apparatusand methods have several features, no single one of which is solelyresponsible for their desirable attributes. Without limiting the scopeof the present apparatus and methods as expressed by the claims thatfollow, their more prominent features will now be discussed briefly.After considering this discussion, and particularly after reading thesection entitled “Detailed Description”, one will understand how thefeatures of the present embodiments provide advantages, which includethe ability to control various restorative parameters during the stagesof planning and delivering orthodontic and prosthodontic treatment, theability to iterate during the planning stages to arrive at varioustreatment goals and to then select a most desired treatment goal,reduced tooth material removed, preservation of future options fororthodontic and/or prosthodontic procedures, improved prosthodonticoutcomes, assisting a dental professional in precisely identifying areasof a patient's dentition to be removed during a prosthodontic procedure,and assisting the dental professional in verifying whether he or she hasremoved enough tooth material to properly seat dental restorations.

One aspect of the present apparatus and methods includes the realizationthat in a prosthodontic procedure it is desirable to control restorativeparameters so that they fall within desired ranges in the finalrestorative outcome. A patient typically has one or more goals that heor she wants to achieve through the prosthodontic procedure. Bycontrolling these parameters both during the planning stages and duringthe delivery of orthodontia/prosthodontia, the patient is more likely tohis or her restorative treatment goals.

Another aspect of the present apparatus and methods includes therealization that in a prosthodontic procedure it is desirable to removeas little healthy tooth material as necessary to ensure a structurallysound final restoration. The removal process is irreversible andpotentially uncomfortable for the patient. Furthermore, subsequentdental work on the same tooth typically requires further removal ofnatural tooth structure. Therefore, it is desirable to remove as littlenatural tooth structure as necessary, since the options for futuremodifications of the patient's dentition become more limited as moretooth material is eliminated. Excessive removal may also lead tocomplications, such as creating a need for endodontic treatment (rootcanal treatment), and compromised retention of the dental restoration.

Another aspect of the present apparatus and methods includes therealization that in a prosthodontic procedure there is a prognosis foreach patient based at least in part on the beginning configuration ofthat patient's dentition. Thus, for patients with severely maloccludedteeth, the restorative prognosis may be poor due at least in part to theseverity of the malocclusion. By treating the patient's dentition firstwith orthodontia prior to performing the prosthodontic procedure, theprognosis for that patient may be significantly improved, because thenew tooth positions may require less structural change, and enable moreenhanced restorative design.

Another aspect of the present apparatus and methods includes therealization that when placing a preparation guide over a patient'sdentition prior to tooth modification, protruding areas of the teeth(areas that are to be removed during the preparation) may prevent theguide from being seated properly unless the areas are actually removed.Thus, it is difficult for the dental professional to identify withprecision, areas of the teeth that are to be removed without actuallycutting the teeth. It is also difficult for the dental professional toprecisely verify whether he or she has removed enough tooth material toproperly create the desired dental restoration(s) to be placed.Therefore, it would be advantageous if the dental professional hadavailable a guide that could be used to measure for adequate preparationclearance while at the same time avoiding protruding areas of thepatient's teeth that would prevent the guide from being seated properlyeven in advance of any tooth modification.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosed embodiments of the present prosthodontic and orthodonticapparatus and methods will now be discussed in detail with an emphasison highlighting the advantageous features. These embodiments depict thenovel and non-obvious apparatus and methods shown in the accompanyingdrawings, which are for illustrative purposes only. These drawingsinclude the following figures, in which like numerals indicate likeparts:

FIG. 1 is a table rating various orthodontic/prosthodontic treatmentoptions against restorative parameters;

FIG. 2 is a schematic illustration of two teeth in a pretreatmentconfiguration;

FIG. 3 is a schematic illustration of the teeth of FIG. 2 in apost-treatment configuration according to one example prosthodontictreatment plan;

FIG. 4 is a schematic illustration of the teeth of FIG. 2 in apost-treatment configuration according to another example prosthodontictreatment plan;

FIG. 5 is a schematic illustration of the teeth of FIG. 2 in apost-treatment configuration according to one exampleorthodontic/prosthodontic treatment plan;

FIG. 6 is a schematic illustration of the teeth of FIG. 2 in apost-treatment configuration according to another exampleorthodontic/prosthodontic treatment plan;

FIG. 7 is a schematic illustration of the teeth of FIG. 2 in apost-treatment configuration according to another exampleorthodontic/prosthodontic treatment plan;

FIG. 8 is a schematic illustration of the teeth of FIG. 2 in apost-treatment configuration according to one example orthodontictreatment plan;

FIG. 9 is a flowchart illustrating steps that may be performed incertain embodiments of the present methods;

FIG. 10 is a perspective view of one embodiment of an aligner that maybe used in connection with certain embodiments of the present apparatusand methods;

FIG. 11 is a flowchart illustrating steps that may be performed incertain embodiments of the present methods;

FIG. 12 is a front elevation view of a tooth in a beginningconfiguration;

FIG. 13 is a front elevation view of the tooth of FIG. 12 superimposedwith a desired final configuration for the tooth, according to oneembodiment of the present methods;

FIG. 14 is a front elevation view of the tooth of FIG. 12 superimposedwith a desired final configuration for the tooth, according to oneembodiment of the present methods;

FIG. 15 is a front elevation view of the tooth of FIG. 12 and oneembodiment of the present prosthodontic apparatus;

FIG. 16 is a front elevation view of the tooth of FIG. 12 and oneembodiment of the present prosthodontic apparatus, illustrating the stepof removing a portion of the tooth that extends beyond the apparatus;

FIG. 17 is a front elevation view of the tooth of FIG. 12 after it hasbeen prepared according to one embodiment of the present methods;

FIG. 18 is a front elevation view of the tooth of FIG. 12 and a dentalrestoration placed in accordance with one embodiment of the presentmethods;

FIG. 19 is a flowchart illustrating steps in another embodiment of thepresent methods;

FIG. 20 is a graph representing the start and stop points which yieldthe least amount of tooth mass removal and/or mass build-up over a givenamount of available treatment time;

FIG. 21 is a flowchart illustrating a process for simulating thecreation of veneer models using orthodontic and prosthodontic techniquesin accordance with one embodiment of the present invention;

FIGS. 22A and 22B are simplified views of a dental arch in apre-treatment configuration and in a final configuration in accordancewith one embodiment of the present invention, respectively;

FIG. 23 is a flowchart illustrating steps in an embodiment of theprocess of FIG. 21;

FIG. 24 shows a simplified side view of a tooth in an Initialconfiguration and a Prepared configuration in accordance with oneembodiment of the present invention;

FIG. 25 shows a simplified side view and a top view of the sweep volumeof a Prepared tooth configuration in accordance with one embodiment ofthe present invention; and

FIG. 26 is a flowchart illustrating a process for preparing an actualrestoration in accordance with the present invention.

DETAILED DESCRIPTION

It should be understood that the techniques of the present invention maybe implemented using a variety of technologies. For example, methodsdescribed herein may be implemented in software executing on a computersystem, or implemented in hardware using either a combination ofmicroprocessors or other specially designed application specificintegrated circuits, programmable logic devices, or various combinationsthereof. In particular, methods described herein may be implemented by aseries of computer-executable instructions residing on or carried by asuitable computer-readable medium. Suitable computer-readable media mayinclude volatile memory (e.g., RAM) and/or non-volatile memory (e.g.,ROM, disk).

Certain embodiments of the present prosthodontic and orthodonticapparatus and methods advantageously combine the benefits of orthodontictreatment with a prosthodontic procedure to enhance the final outcome ofthe procedure. The embodiments produce a healthy-looking smile with areduced amount of tooth structure removed as compared to a traditionalprosthodontic procedure with no orthodontia. The reduction in toothstructure removed reduces complications that can arise fromover-reduction of teeth, such as sensitivity. It also helps to ensurethat the reduction may be performed in an accurate, reproducible manner.Further, the options for future modifications of the patient's dentitionare increased, since a greater proportion of the patient's originaldentition remains after the procedure has been completed.

Certain other embodiments of the present apparatus and methodsadvantageously enable one or more restorative parameters to becontrolled during a prosthodontic procedure. Upon identifying one ormore parameters of interest, a dental professional can iterate processesof virtual orthodontia and virtual prosthodontia to observe whether eachiteration produces a desired outcome for the parameter(s) of interest.The dental professional may perform the iterations together with thepatient. The parameters of interest may include, for example, time oftreatment, volume of tooth structure removed, final aesthetics and/oralignment of lingual tooth surfaces or other parameters.

Certain other embodiments of the present apparatus and methodsadvantageously assist a dental professional in identifying areas of apatient's dentition to be removed during a prosthodontic procedure. Thepresent embodiments also assist the dental professional in verifyingwhether he or she has removed enough tooth material to properly createdental restoration(s) that are to be placed. The prosthodontic methodsdescribed herein may be performed on a patient's entire dentition or onjust one tooth. For simplicity, however, some of the present apparatusand methods are shown in the figures with reference to only a singletooth.

Certain other embodiments of the present apparatus and methodsadvantageously assist a dental professional in forming an orthodontictreatment plan oriented on optimal veneer usage. These embodimentsassist the dental professional in quantifying parameters used toproperly create dental restoration(s) that are to be placed.

Treatments

Embodiments of the present methods may begin when a patient firstconsults a dental professional (which may include, but is not limitedto, a dentist, an orthodontist, a lab technician, a dental productprovider, a dental service provider and the like) regarding anorthodontic procedure and/or a prosthodontic procedure. During theinitial consultation, the dental professional and the patient maydiscuss the patient's treatment goal(s) and any constraints that mightlimit the range of available treatment options. For example, the patientmay desire to have his or her smile enhanced prior to his or herwedding, but the patient may not consult the dental professional untilsix months prior to the wedding. In such a situation, the timeframe fortreatment is limited, and an appropriate orthodontic/prosthodontictreatment plan must be set to fit within the timeframe.

In the table of FIG. 1, the left-hand column lists sevenorthodontic/prosthodontic treatment options represented by the lettersA-G. Options A-G are schematically illustrated in FIGS. 2-8, which arediscussed in detail below. The top row of the table lists fourrestorative parameters that may be of interest to the patient. Theexemplary four restorative parameters are: time required to complete theorthodontic/prosthodontic treatment, reduction in volume of toothstructure resulting from prosthodontic treatment, final aesthetics uponcompletion of treatment (including teeth color, realistic thickness ofteeth and the like), and alignment of lingual tooth surfaces (on tongueside of teeth) upon completion of treatment. As explained in detailbelow, the table assesses each of the treatment options by assigningqualitative values to each of the restorative parameters for thattreatment option. Those of ordinary skill in the art will appreciatethat there may be additional restorative parameters not listed in FIG. 1that may be of interest to some patients. Accordingly, the listedparameters should not be interpreted as limiting the scope of thepresent embodiments.

In FIG. 1, each of the orthodontic/prosthodontic treatment options israted against the four listed parameters. To assess a given treatmentoption, the dental professional and/or patient locates that option inthe leftmost column and reads across the table. The symbols appearing ineach column indicate whether the treatment option produces a positiveoutcome or a negative outcome for the parameter of that column. If atreatment option produces a positive outcome for a given parameter, oneor more + signs appear in the column for that parameter. If a treatmentoption produces a negative outcome for a given parameter, one or more −signs appear in the column for that parameter. Multiple + or − signsindicate that that parameter is particularly positive or particularlynegative for that treatment option. If a 0 appears in a column, thenthat parameter is considered neutral with respect to that treatmentoption.

FIG. 2 schematically illustrates a first tooth X and a second tooth Y ina pretreatment configuration, while FIGS. 3-8 illustrate the same teethin various post-treatment configurations. In FIGS. 2-8, the illustratedteeth are molars, and the cuspal (chewing) surface of each molar facesthe viewer. The lingual (tongue side) surface of each tooth facesdownward, and the buccal (opposite the tongue side) surface of eachtooth faces upward.

In the pretreatment configuration of FIG. 2, tooth X is positionedcloser to the tongue than tooth Y. Thus, neither the lingual surfacesnor the buccal surfaces of the teeth are aligned. Further, a portion oftooth Y is overlapping a portion of tooth X. Thus, to align the lingualand buccal surfaces of the teeth, either the teeth must first be movedaway from each other, or the overlapping portions of one or both teethmust be removed.

FIG. 1 includes option A, which represents no orthodontic orprosthodontic treatment and provides a baseline from which to relativelymeasure other outcomes. Thus, the teeth remain as they appear in FIG. 2.Referring to the table in FIG. 1 and reading across the first row,option A produces a very strongly positive outcome (+++) for the timerequired to complete the treatment, because there is no treatment.Option A also produces a very strongly positive outcome (+++) forreduction in volume of tooth structure, because no tooth structure isremoved. Finally, treatment option A produces strongly negative outcomes(−−−) for both final aesthetics and alignment of lingual tooth surfaces,because no improvements are made in these areas.

FIG. 3 schematically illustrates one treatment plan that involves onlyprosthodontics. To transform the teeth from the configuration of FIG. 2into the configuration of FIG. 3, the overlapping portion of tooth Y iscut or ground away, and a veneer is applied to the buccal surface oftooth X. In order to firmly secure the veneer to the tooth, smallportions on either side of tooth X are removed to form butt joints withthe veneer.

Referring to the table in FIG. 1 and reading across the second row,treatment option B produces a strongly positive outcome (++) for thetime required to complete the treatment, because the treatment involvesonly prosthodontia, which may be completed in a much shorter timeframethan orthodontia. However, treatment option B produces a negativeoutcome (−) for reduction in volume of tooth structure, since theoverlapping portion of tooth Y is removed and small portions on eitherside of the tooth X are removed to form the butt joints. Treatmentoption B produces a more negative outcome (−−) for final aesthetics,since a very thick veneer is added to tooth X, and since there is nomatching veneer added to tooth Y. Thus, the color of tooth Y is notimproved, and there may be some color contrast between the buccalsurfaces of teeth X and Y. Finally, treatment option B produces a verystrong negative outcome (−−−) for alignment of lingual tooth surfaces,the misalignment of the lingual surfaces is not corrected at all.

FIG. 4 schematically illustrates another treatment plan that alsoinvolves only prosthodontics. To transform the teeth from theconfiguration of FIG. 2 into the configuration of FIG. 4, theoverlapping portion of tooth Y is ground away, and a veneer is appliedto the buccal surface of tooth X. In this embodiment, a veneer is alsoapplied to the buccal surface of tooth Y. As in treatment option Babove, small portions on either side of tooth X are removed to form buttjoints with the veneer. To secure the veneer to tooth Y, a thin wall ofthe buccal surface of tooth Y is removed in addition to small portionson either side of tooth Y for butt joints.

Referring to the table in FIG. 1 and reading across the third row,treatment option C produces a strong positive outcome (++) for the timerequired to complete the treatment, because the treatment involves onlyprosthodontia. Treatment option C produces a strong negative outcome(−−) for reduction in volume of tooth structure, because not only is theoverlapping tooth structure of tooth Y removed, but tooth structure isremoved from tooth X and tooth Y to form butt joints and to make roomfor the veneer on tooth Y. Treatment option C produces a neutral outcome(0) for final aesthetics, because although there is a very thick veneeradded tooth X, the color of both teeth are improved because of thematching veneers. Finally, like treatment option B treatment option Calso produces a very strong negative outcome (−−−) for alignment oflingual tooth surfaces.

In order to arrive at the best possible outcome for a patient's specificcondition or treatment requirements, trade-offs may be made between eachof the restorative parameters. It is apparent that for some situationswhere, for example, aesthetics and lingual alignment are importantparameters, and particularly where it is desired to minimize the amountof tooth reduction, some combination of orthodontics and prosthodonticsmay be indicated.

FIG. 5 schematically illustrates another treatment plan that involvesboth orthodontics and prosthodontics. To transform the teeth from theconfiguration of FIG. 2 into the configuration of FIG. 5, theoverlapping portion of tooth Y is ground away, and tooth X is movedforward (away from the tongue). However, tooth X is only moved forwardthrough the distance d, such that while alignment of the buccal andlingual surfaces of the teeth is improved, it is not made perfect. Intreatment option D veneers are also applied to the buccal surfaces ofteeth X and Y.

Referring to the table in FIG. 1 and reading across the fourth row,treatment option D produces a positive outcome (+) for the time requiredto complete the treatment, because although the treatment involvesorthodontia, the treatment nevertheless takes less time than a treatmentoption that involves more movement of tooth X. Treatment option Dproduces strong negative outcome (−−−) for reduction in volume of toothstructure, because not only is the overlapping tooth structure of toothY removed, but tooth structure is removed from tooth X and tooth Y toform butt joints and to make room for the veneer on tooth Y. Treatmentoption D produces a positive outcome (+) for final aesthetics, since,due to the movement of tooth X, relatively thin veneers are added toboth teeth. Finally, treatment option D produces a positive outcome (+)for alignment of lingual tooth surfaces, because the alignment isimproved over that of the pretreatment configuration.

FIG. 6 schematically illustrates another treatment plan that alsoinvolves both orthodontics and prosthodontics. To transform the teethfrom the configuration of FIG. 2 into the configuration of FIG. 6, theoverlapping portion of tooth Y is ground away, and tooth X is movedforward (away from the tongue). In contrast to treatment option D, toothX is moved forward through the distance D until the lingual surfaces ofthe teeth align. In treatment option E, veneers are also applied to thebuccal surfaces of teeth X and Y.

Referring to the table in FIG. 1 and reading across the fifth row,treatment option E produces a negative outcome (−) for the time requiredto complete the treatment, because the treatment involves orthodontia tomove tooth X through a greater distance D when compared to othertreatment options. Treatment option E produces a strong negative outcome(−−) for reduction in volume of tooth structure, because not only is theoverlapping tooth structure of tooth Y removed, but tooth structure isremoved from tooth X and tooth Y to form butt joints and to make roomfor veneers on both tooth X and tooth Y. Treatment option E produces astrong positive outcome (++) for final aesthetics, because thin veneersare added to both teeth and both teeth appear to be of normal thickness.Finally, treatment option E produces a strongly positive outcome (++)for alignment of lingual tooth surfaces, because the alignment isgreatly improved over that of the pretreatment configuration.

FIG. 7 schematically illustrates another treatment plan that involvesorthodontics and prosthodontics. To transform the teeth from theconfiguration of FIG. 2 into the configuration of FIG. 7, the teeth aremoved away from one another (as represented by the oppositely directedarrows on either side of the teeth) and tooth X is moved forward (awayfrom the tongue) through the distance D until the buccal and lingualsurfaces of the teeth align. However after the teeth are moved,treatment option F includes adding veneers to the buccal surfaces oftooth X and tooth Y.

Referring to the table in FIG. 1 and reading across the sixth row,treatment option F produces a strong negative outcome (−−) for the timerequired to complete the treatment, because the treatment involvesorthodontia to move tooth X through a distance D and to move tooth Xaway from tooth Y. Treatment option F produces a very neutral outcome(0) for reduction in volume of tooth structure, because only a smallamount of tooth structure is removed on from tooth X and tooth Y to formbutt joins for the veneers. Treatment option F produces a very strongpositive outcome (+++) for final aesthetics because the teeth areproperly aligned, the teeth appear to be of normal thickness and theveneers correct any discoloration or misshapenness from the pretreatmentconfiguration. Finally, treatment option F produces a strong positiveoutcome (++) for alignment of lingual tooth surfaces, because thealignment is greatly improved over that of the pretreatmentconfiguration.

FIG. 8 schematically illustrates another treatment plan that involvesonly orthodontics. To transform the teeth from the configuration of FIG.2 into the configuration of FIG. 8, the teeth are moved away from oneanother (as represented by the oppositely directed arrows on either sideof the teeth) and tooth X is moved forward (away from the tongue)through the distance D until the buccal and lingual surfaces of theteeth align.

Referring to the table in FIG. 1 and reading across the seventh row,treatment option G produces a strong negative outcome (−−) for the timerequired to complete the treatment, because the treatment involvesorthodontia to move tooth X through a distance D and to move tooth Xaway from tooth Y. Treatment option G produces a very strong positiveoutcome (+++) for reduction in volume of tooth structure, because notooth structure is removed. Treatment option G produces a positiveoutcome (+) for final aesthetics because the teeth are properly alignedand appear to be of normal thickness. However, because no veneers areadded to the teeth, any discoloration or misshapenness from thepretreatment configuration remains. Finally, treatment option G producesa strong positive outcome (++) for alignment of lingual tooth surfaces,because the alignment is greatly improved over that of the pretreatmentconfiguration.

While the examples described with respect to FIGS. 2-8 relate to twoteeth, similar principals apply to other configurations of maloccludedand misshapen teeth and apply to patient with two or more maloccludedteeth.

After the initial consultation between the patient and the dentalprofessional, the dental professional and the patient may develop anorthodontic treatment plan and/or a prosthodontic treatment plan. Theorthodontic treatment plan may transform the patient's dentition fromits beginning configuration to an intermediate configuration, and theprosthodontic treatment plan may transform the patient's dentition fromthe intermediate configuration to a final configuration. Theintermediate configuration may also be referred to as an orthodontictreatment goal, and the final configuration may also be referred to as arestorative treatment goal.

With reference to FIG. 9, a computer-generated, three-dimensional,virtual model of the patient's dentition in the beginning configurationis created, as shown at step S10. Unlike some 3-D educational softwarewhich show representative “typodont” models for illustrative purposes,this model represents the patient's actual dentition in a beginningconfiguration. The virtual model may be generated prior to any toothpreparation, so that the model represents the patient's dentition in apretreatment state. Some processes for making such a virtual model aredescribed in, for example, U.S. Patent Application Publication No. US2006/0154207, published on Jul. 13, 2006 and in U.S. patent applicationSer. No. 11/678,749, filed on Feb. 26, 2007 by Kaza et al. The entiredisclosures of the '207 publication and the '749 application are herebyincorporated herein by reference.

With continued reference to FIG. 9, the virtual model of the beginningconfiguration using virtual orthodontia may be transformed to create acomputer-generated, three-dimensional, virtual model of the patient'sdentition in an intermediate configuration, as shown at step SI2. Thevirtual orthodontia may include manipulation and movement of teeth inthe virtual model. The virtual model of the intermediate configurationmay be transformed using virtual prosthodontia to create acomputer-generated, three-dimensional, virtual model of the patient'sdentition in a desired final configuration, as shown at step S14. Thevirtual prosthodontics may include one or more modifications of thevirtual model, such as tooth mass removal or build-up and/or theplacement of one or more dental restorations. Those of ordinary skill inthe art will appreciate that steps S12 and S14 may be performed in anyorder, and may even be performed simultaneously. In addition, steps S12and S14 may be iterated upon. During each iterative step, the finalmodel may be evaluated and iterated again or finalized into a treatmentplan. These iterative steps are described in greater detail below withrespect to FIG. 11.

Finalizing a treatment plan may include setting the intermediate andfinal configurations, as shown at step S16 in FIG. 9. Once theseconfigurations are set, the orthodontic treatment plan and theprosthodontic treatment plan are generated, as shown at step SI8. Theorthodontic treatment plan may transform the dentition from thebeginning configuration to the intermediate configuration, and theprosthodontic treatment plan will transform the dentition from theintermediate configuration to the final configuration or restorativetreatment goal.

Once the treatment plan is finalized, the next step in the presentmethod may be to deliver a course of orthodontic treatment according tothe orthodontic treatment plan, as shown at step S20 in FIG. 9. Theorthodontia may proceed using any well-known apparatus and methods, suchas orthodontic brackets and wires (braces). Alternatively, or inaddition, the orthodontia may include a series of plastic orthodonticappliances or aligners. FIG. 10 illustrates one such aligner 50 that isadapted to fit over a patient's lower arch 52. The aligners, each ofwhich may be a polymeric shell having a teeth-receiving cavity, aredescribed in detail in the '893 patent and the '807 patent, both ofwhich are incorporated herein by reference above. The patient wears theseries of aligners in order to achieve incremental repositioning ofindividual teeth in his or her jaw.

The polymeric aligner 50 of FIG. 10 may be formed from a thin sheet of asuitable elastomeric polymer, such as Tru-Tain 0.030″ thermal formingdental material, available from Tru-Tain Plastics of Rochester, Minn.Other aligner materials can include, but are not limited to polyester,polyurethane, polypropylene, polycarbonate, poly-blend, andpoly-laminates. Usually, no wires or other structures are provided forholding the aligner in place over the teeth, though it may be possibleto incorporate auxiliary devices such as wires, hooks, and elastics intothe aligners to assist in appliance retention. It is also possible toprovide individual anchor attachments directly on the teeth, withcorresponding receptacles or apertures in the aligner so that thealigner can apply either a retentive or a supplemental force on thetooth that would not be possible in the absence of such an anchor.

The aligners are generated using data representing the patient's teeth.The data may be from scans of dental impressions, dental casts, and/ordirect scans of the patient. Each polymeric shell may be configured sothat its tooth-receiving cavity has a geometry corresponding to anincremental tooth arrangement intended for the patient. The patient'steeth are repositioned from their initial arrangement to the nextincremental arrangement by placing the aligners sequentially over theteeth. The patient wears each aligner until the teeth have conformed tothe position defined by the aligner. At that point, the patient movesonto the next aligner stage of the planned course of treatment andreplaces the old aligner with the next aligner in the series until theintended treatment outcome is achieved. The course of treatment mayrequire a recalibration scan and additional aligners if the teeth do notexactly track according to the design within the aligner. However,because the aligners are removable and not bonded to the teeth, theprocess is convenient and hygienic for the patient, generally more sothan traditional braces, which are affixed directly to the teeth and notintended to be removed by the patient during the course of treatment.

The polymeric shell can fit over any and typically all teeth present inthe upper or lower jaw. Often, only a select few of the teeth arerepositioned at a given time while remaining teeth provide a base or ananchor region for holding the aligner in place as the aligner applies arepositioning force against the tooth or teeth to be repositioned. Inmany cases, all teeth may be repositioned at some point during thetreatment. In such cases, the moved teeth may also serve as a base oranchor region for holding the aligner.

Upon completion of the orthodontic treatment plan, a dental professionalmay perform one or more prosthodontic procedures according to theprosthodontic treatment plan. As part of the prosthodontic procedure(s),the dental professional prepares the necessary teeth by reducing thetooth surfaces as needed to ensure proper retention, strength, andaesthetics for the final restoration. The prepared teeth may require oneor more provisional restorations. In some situations, however, the finalrestoration(s) may be immediately fabricated in the dentalprofessional's office and placed without the need for any provisionals.An example of an immediate fabrication system is the Siriona CEREC™milling machine, which uses an in-office scan of the prepared dentition,the creation of a virtual restoration over the preparation scan, and themilling of a porcelain block according to the virtual restoration inconsideration of the preparation scan.

Prior to placing the dental restoration(s) on the patient's dentition,at least one of tooth surface removal, cutting and/or reshaping may beperformed, as shown in step S22 in FIG. 9. The removal/cutting/reshapingprepares the dentition to receive the dental restoration(s). Asdiscussed above, such preparation generally involves the removal of atleast a portion of a tooth, its enamel and/or dentin, and some or allpre-existing restorations on the tooth. The reshaping may also involvebuilding up some areas of the dentition using biocompatible materialssuch as composite, fiberglass, carbon fiber, gold, amalgam, titanium,and/or stainless steel. When removing tooth material to accommodate adental restoration, generally 1 mm of tooth material is removed toensure adequate restoration strength and desired aesthetics. However, asthose of ordinary skill in the art will appreciate more or less toothmaterial may be removed.

During the steps of removal/cutting/reshaping, the accuracy and designof the removal, cutting and/or reshaping may be periodically verified.In one embodiment, one or more preparation guides may be positioned overthe patient's dentition. The preparation guide, which resembles analigner and is typically manufactured in a similar way, may embody thefinal restorative configuration. Clearances between teeth surfaces andthe preparation guide may be measured to verify that the desired amountsof tooth surface have been removed. To determine whether adequate toothmaterial has been removed, the guide may be seated on the teeth and anyinterference between the tooth and the guide may be removed. Once theguide is fully seated, the clearances between the guide and the teethare checked and additional tooth material is removed until adequateclearances are achieved between the inner surfaces of the guide and thesurfaces of the teeth receiving the final restoration(s).

After the desired amount of tooth material has been removed inconjunction with the preparation guide, a provisional or finalrestoration may be prepared and affixed on the patient's dentition, asshown in step S24 in FIG. 9. An adhesive, such as dental cement, may beused to affix the restoration on the teeth to prevent it from leakingand/or dislodging.

As described above, in the foregoing methods at least some of the stepsmay be performed in an iterative fashion, and may include one or moresub-steps. The iteration enables a dental professional and a patient tofocus on one or more restorative parameters that are of interest to thepatient, and to control the outcome of the treatment with respect tothese parameters. Therefore, prior to or during the present methods thedental professional and the patient may identify one or more restorativeparameters that are of interest to the patient. As discussed above withrespect to FIG. 1, these parameters may include: treatment time, volumeof tooth structure removed, final aesthetics and/or alignment of lingualtooth surfaces. Moreover, after creating a virtual model of thepatient's dentition in the beginning configuration (step S10, FIG. 11),the dental professional may transform the virtual model to createvirtual models representing the desired intermediate configuration (SI2)and final configuration (SI4). In addition, at step S26 the dentalprofessional may evaluate the one or more restorative parameters ofinterest, and then iterate the movement steps and again evaluate therestorative parameter(s). The dental professional and the patient mayrepeat these iterative steps until the restorative parameter(s) fallwithin desired ranges. Again, those of ordinary skill in the art willappreciate that the iterative steps outlined above may be performed inany order.

In step S26, the evaluation step may focus on the total volume of toothstructure removed in order to reach the final configuration. Theevaluation may be based on, for example, a desired threshold of thetotal volume of tooth structure. For example, the dental professionalmay begin by superimposing the dentition in the intermediateconfiguration and the dentition in the final configuration to identifyon the superimposed models the intersection boundaries at the areaswhere the dentition of the intermediate configuration protrudes beyondthe dentition of the final configuration. Using the three-dimensionalgeometrical models, the volume of the protruding tooth structure may becalculated. The volume of the protruding dentition represents the volumeof tooth structure that may be removed by the dental professional duringthe prosthodontic procedure.

As a result of the evaluation and visualization, the dentalprofessional, perhaps after consulting the patient, may modify theorthodontic treatment plan by moving and aligning the teeth usingvirtual orthodontics into a configuration that varies from theorthodontic treatment goal. The dental professional may also modify theprosthodontic treatment plan by modifying the teeth using virtualprosthodontics into a configuration that varies from the restorativetreatment goal. The dental professional may repeat these steps severaltimes. In addition, or in the alternative, as a result of the evaluationand visualization, the dental professional may modify the orthodontictreatment goal and/or the restorative treatment goal. For example, thedental professional may modify the restorative treatment goal bymodifying the desired final tooth position goal and/or tooth shape goal.

In step S26 the dental professional may superimpose the modified modelsto determine the impact of the modifications on the volume of toothstructure that extends outward from the intersection boundaries. Thedental professional may continue to modify the virtual representationsof the tooth structures in both the virtual orthodontic plan and virtualrestorative goal models until the dental professional has iterativelyarrived at an acceptable preparation design that provides for a desiredthreshold value of the parameters of interest. In the present invention,the threshold value represents either a maximum, or if appropriate, aminimum condition that the dental professional determines is anacceptable variation to any given restorative parameter. For example,the dental professional may set a threshold value that represents themaximum amount of the total volume of the tooth structure to be removedto create the final tooth configuration. A threshold value may also be,for example, the maximum amount of time available for treatment or themaximum thickness of a veneer to be placed on a tooth.

The ability to virtually iterate the preparation specifications asapplied to the virtual beginning model of the dentition as provided insteps S12 and S14 provides the dental professional the ability to modifythe preparation design prior to any actual moving or cutting of theteeth. In addition, the dental professional may also visualize theimpact of the preparation to the actual tooth, for example, in terms ofvolume of tooth material removed, the different areas of tooth affected,and the depth of the preparation, which is advantageous for avoidingsensitivity or other treatments, such as root canals.

Once the dental professional has arrived at a preparation design thatmeets desired thresholds for the restorative parameters of interest,then the dental professional may set the intermediate and finalconfigurations, as shown at step S28. The dental professional may thenmap out the orthodontic and prosthodontic treatment plans based upon thebeginning, intermediate and final configurations, as shown at step S30.

Using the orthodontic and prosthodontic treatment plans, the dentalprofessional may next create, or have created, orthodontic appliancesand restorative preparations, as shown at step S32. Steps S20, S22 andS24 may then proceed as shown in FIG. 11 and as described above withrespect to FIG. 9.

Many of the various embodiments included in the method steps describedwith reference to FIGS. 9 and 11 are illustrated in the followingexample.

In accordance with one embodiment of the present methods, a dentalprofessional may begin a restorative procedure, by first meeting with apatient to determine which of the restorative factors available areachievable to the degree desired by the patient given the patient'streatment priorities. For example, the patient may present to thedentist having a malocclusion like that shown in FIG. 2. In thisexample, the patient may explain to the dentist that she is anticipatinga wedding day that is only six months in the future. The bride-to-bewants her teeth (tooth X and Y, in this example) to appear as white andas straight as possible, but she is not concerned with the lingualsurface of her teeth as it does not bother her in its present condition.The dental professional notes that the patient has relatively unhealthyteeth and thus determines that the degree of tooth volume reduction, ifneeded, should be minimized.

The dental professional may apprise the patient with her options, whilereferring to the table in FIG. 1. Of the options available, the dentalprofessional mentions that Options B and C provide the best desiredoutcome regarding time of treatment in keeping with the patient'ssix-month timeframe. However, the dental professional may explain thatOption B is not as aesthetically desirable as Option C, since Option Bdoes not provide for a matching veneer between the subject teeth. Thedental professional may also explain that Options B and C require arelatively thick veneer be placed on one of the subject teeth to createthe illusion that the buccal surface of the teeth are properly aligned.

The patient reviews Options B and C and determines that Options Cprovides a semi-satisfactory solution, but that the thick veneer isproblematic for her. The dental professional may then suggest that thethickness of the veneer may be reduced by moving the subject teethfirst, as in Option D. The patient asks to visualize the anticipatedresults.

To begin, the dental professional scans or photographs the patient'sactual dentition to create the virtual model and inputs the data into acomputer running the modeling software.

The dental professional may then manipulate the virtual beginning modelusing the computer software, to simulate the effect of orthodontictreatment by virtually repositioning the subject teeth, tooth X andtooth Y, into a different position. In this example, the dentalprofessional determines that to expedite tooth movement, the portion oftooth Y that overlaps tooth X is to be removed.

Using the software model, the dental professional may quantify adistance dj (FIG. 5) that may be achieved in the prescribed timeframe(e.g. 6 months), which requires a certain amount of tooth volumereduction Vi, and yields a veneer thickness Tj. The dental professionalmay then manipulate the tooth X and tooth Y again to generate a distance62 that may be achieved in the prescribed timeframe, which requires anamount of tooth volume reduction V2 and yield a veneer thickness T2 andso on until the dental professional decides that he has generated anumber of suitable options (d_(1 . . . n), V_(1 . . . n), T_(1 . . . n))for the patient to review. Since the dental professional is concernedwith the amount of tooth volume reduction, the dental professional mayset a threshold value for the amount of tooth volume reduction (V₁, V₂ .. . V_(n)) that he has determined is tolerable for this patient.

Next, the dental professional, in consultation with the patient, mayreview the options and visualize the results, to determine, whichprovides a reduction to the thickness of the veneer to the patient'ssatisfaction. If the patient is satisfied, and the dental professionaland the patient have agreed upon the desired final configuration for thedentition, the dental professional may then use the computer software tocreate a suitable prescription for moving the patient's teeth.

In the above example, before finalizing the prescription, the patientinforms the dental professional that her wedding plans have beencanceled, but that she still desires to have her teeth restored withinthe next 12 months. The dental professional explains that, since thereis more time available for an orthodontic procedure, the patient hasmore options to choose from with regard to the restoration, for example,Options E, F, and G of FIG. 1.

The dental professional then revisits the virtual model of the patient'sdentition and again begins to manipulate the teeth to determine, asbefore, which Options now provide the patient with the most suitableoutcome given the new timeframe.

Preparation Guides

Although not shown in FIG. 11, the treatment plans could also be used tocreate preparation guides or templates to help in the restorative aspectof tooth preparation, temporary restoration creation and creation ofvirtual wax-ups and possible final veneers. An example of a preparationguide that could be created using the treatment plans is discussed belowwith reference to FIGS. 12-19.

FIG. 12 illustrates a tooth 20 in a beginning configuration, prior toany prosthodontic modifications. In accordance with one embodiment ofthe present methods, a dental professional may begin a prosthodonticprocedure by creating a first virtual model of a patient's dentition ina beginning configuration, as shown at step SI00 in FIG. 19. The virtualmodel may be generated by digitally scanning and/or photographing theactual dentition and inputting the data into a computer running modelingsoftware. The dental professional may store the beginning model for usein a comparison, as described below.

The dental professional may then manipulate the virtual beginning modelusing the computer software, as shown at step SI02. This manipulationmay include simulating the effect of orthodontic treatment by virtuallyrepositioning one or more teeth into a different position, such that theamount of tooth reduction necessary becomes reduced or more balanced forthe desired restorative outcome. On the computer screen, the dentalprofessional may also remove portions of the teeth and/or build-up otherportions of the teeth in order to generate a second virtual model of thepatient's dentition in a desired final configuration (SI02). Afterconsultation with the patient (SI04), the dental professional mayperform additional modifications to the second virtual model (S106)until the dental professional and the patient agree on the desired finalconfiguration.

FIG. 13 illustrates one example of tooth modifications with which thedental professional may experiment, and about which the dentalprofessional and the patient may confer. In FIG. 13, the tooth 20 isshown in the beginning configuration (solid lines) and in one possiblefinal configuration (dashed lines). To reach the final configuration thedental professional applies a dental restoration to the tooth 20. In theillustrated embodiment, the dental restoration is a veneer 22. However,those of ordinary skill in the art will appreciate that the presentmethods may involve the placement of any type of dental restoration,such as a bridge or a crown. Before placing the veneer 22 on the tooth20, the dental professional prepares the tooth 20 by removing somesurface material. For example, the dental professional may need tocompletely cut off a portion 24 (upper shaded portion) of the tooth 20that would extend past the veneer 22. In other areas 26 (lower shadedportions) the dental professional may need to remove just a portion ofthe tooth surface (generally about 1 mm) in order to create room for theveneer.

Once the dental professional and the patient have agreed upon thedesired final configuration for the dentition, the dental professionalmay then use the computer software to superimpose the first (beginning)and second (final) virtual models, as shown at step SI08 in FIG. 19. Forexample, FIG. 14 illustrates a model of a final configuration includingthe veneer 22 superimposed over a model of the actual configuration ofthe tooth 20. In the superimposed models, the portion 24 of thebeginning dentition protrudes beyond the veneer 22. The dentalprofessional will remove the protruding portion 24 from the patient'sactual dentition during the prosthodontic procedure.

To enhance the precision with which he or she removes protrudingportions of the patient's dentition, the dental professional may use thesuperimposed models to generate a preparation guide that emphasizes theprotruding portions. The preparation guide may be an overlay thatsubstantially conforms to the second dentition model, but includesapertures that enable protruding portions of the actual dentition toextend beyond the overlay so that they do not interfere with the properseating of the overlay upon the dentition.

To generate the overlay, the dental professional may begin byidentifying on the superimposed models the intersection boundaries atthe areas where the dentition of the first model protrudes beyond thedentition of the second model, as shown at step SI 10 in FIG. 19. Forexample, FIG. 14 illustrates one intersection boundary 28 between thetooth 20 and the veneer 22. The modeling software may be programmed toidentify these boundaries and to highlight them for the dentalprofessional. The portion 24 of the dentition that extends outward fromthe intersection boundary 28 will be removed by the dental professionalduring the prosthodontic procedure.

Once the intersection boundaries have been identified, a preparationguide may be fabricated that substantially conforms to the second modelbut includes apertures defined by the intersection boundaries, as shownat step SI 12 in FIG. 19. An example of a preparation guide or overlay30, for a single tooth 20 is illustrated in FIG. 15. The overlay 30includes a wall portion 32 forming a cavity 34 configured to receive thetooth 20. The preparation guide 30 includes an aperture 36 thatcorresponds to the intersection boundary 28 shown in FIG. 14. Theapertures 36 allow the protruding portions 24 of the tooth 20, to extendthrough the aperture 36. The protruding portions 24 thus to notinterfere with proper seating of the guide 30 upon the tooth 20 in theconfiguration prior to removal of any tooth material. Guide 30 may beplaced over tooth 20 to quickly and efficiently identify protrudingportions 24 that are to be removed.

After placing the preparation guide 30 over the tooth 20 (step SI 14 inFIG. 19), the dental professional removes the protruding portion 24(step SI 16). FIG. 16 illustrates the tooth 20 after removal of theprotruding portion and with the preparation guide 30 still in place.Using the guide 30 over the tooth 20 as shown, the dental professionalcan remove the protruding portion of the tooth 20 with greater precisionas compared to a procedure involving no overlay. The dental professionalsimply cuts or grinds down any portions of the tooth 20 that extendbeyond the overlay 30. The overlay 30 thus not only highlights theportions of the tooth 20 to be removed, but it also shields portions ofthe tooth 20 that are not to be removed, thereby preventing unnecessarytooth reduction.

If a dental restoration 22 is to be placed over the tooth 20, the dentalprofessional also removes portions 26 of the tooth 20 in order to createspace for the veneer 22, as shown in FIG. 16 and at step SI 18 in FIG.19. The dental professional may use the guide 30 to ensure that theremoved tooth portions provide adequate thickness for the veneer 22. Forexample, the dental professional may place the guide 30 over the tooth20 as shown in FIG. 16, perforate the guide 30, and measure with a probethe distances between the tooth 20 and the inner surfaces of the guide30. When the tooth 20 has been fully prepared, as shown in FIG. 17, thedental professional applies the veneer 22, as shown in FIG. 18 and atstep SI20 in FIG. 19.

The guide 30 may be fabricated using any well known method or suitabletechnique, for example, a rapid prototyping method or a moldingtechnique. During the fabrication process, the apertures 36 in the guide30 may be produced as the guide 30 is formed, or they may be cut out ofthe guide 30 after it has been formed.

A given guide may include just one aperture or a plurality of apertures.The boundaries of the aperture(s) may be electronically determined andthe locations provided to cutting machinery to remove material at theaperture locations. Alternatively, the borders of the aperture(s) may bemarked on the guide during the fabrication process so the dentalprofessional may cut out the material at the aperture locations himself.The marking may be performed using ink and/or laser marking, forexample.

Those of ordinary skill in the art will appreciate that the guide 30described above may be used in conjunction with any of the methodsdescribed above. For example, the guide 30 may be employed during stepS22 shown in FIGS. 8 and 10. Alternatively, the guide 30 may be used inother methods not disclosed herein. When used in conjunction with amethod including an orthodontic treatment plan and a prosthodontictreatment plan, such as certain embodiments of the methods describedabove, the dental professional may construct the guide 30 bysuperimposing the virtual model of the patient's dentition in theintermediate configuration with the virtual model of the patient'sdentition in the final configuration. Alternatively, the dentalprofessional may construct the guide 30 by superimposing the virtualmodel of the patient's dentition in the beginning configuration with thevirtual model of the patient's dentition in the final configuration.Intersection boundaries of the two superimposed virtual models woulddefine the locations of the apertures 36 in the guide 30.

Simulated Veneers

A simulated veneer may be generated automatically for all orthodonticset-ups, including retrospective set-ups, such that a library of modelsmay be created systematically for the purpose of diagnosis and screeningfor potential veneer cases. The automated models may be measured interms of, for example, volume, area and thickness, to bettercharacterize the impact of veneer placement to the dentition prior, toinitiating treatment. The simulated veneers allow doctors to avoidunnecessary movement of the teeth and removal of excessive amounts oftooth structure.

In one embodiment, orthodontic and prosthodontic procedures may becombined virtually to create simulated veneers. Using an orthodonticprocedure, a starting and stopping point for a veneering procedure maybe determined. Thus, a virtual simulated veneer may be created using aFinal alignment position relative to an Initial tooth position. Thus,the method described uses three points of data: Initial position,simulated or actual Prepared position (tooth material removed), Finalalignment position (or any other intermediate position).

The Initial and the Prepared positions are superimposed to determine thedifference in volume between the tooth in its Initial position and thetooth in the Prepared position. The difference represents the amount oftooth structure removed (or needed to be removed). Thus:

V_(r) = Vi − V_(p)where Vj is the initial tooth volume, V_(p) is the prepared toothvolume, and V_(r) is the volume removed or preparation volume.

The Initial position and the Final alignment position may also besuperimposed relative to a reference to define a sweep path from theInitial position to the Final alignment position for each tooth. Thereference may be a static tooth, rugae, gingival and the like. The sweeppath defines a swept volume (V_(s)), which represents the union of theprepared tooth volume and restorative structure volume (restorationvolume) that is to be created. The swept volume may need to be modifiedto assure that the swept volume of the tooth does not intersect theswept volume of a neighboring tooth or veneer.

The tool predicts the restoration volume (V_(res)) as follows:

V_(res) = V_(s) − Vpwhere, the V_(p) is subtracted from the V_(s) in order to create thetotal restoration volume, V_(res)

The V_(re)s, V_(s), V_(p), V_(r) may all be formed as separategeometrical models apart from the tooth. Using features of the tool, theV_(res) (simulated veneer), for example, may be manipulated throughshape modification, as well as color modification. The simulated veneermay also be printed as a physical 3-D graphic or formed as a 3-D solidmodel.

Advantageously, the veneer-related quantification may be used as thereference for a veneering review, evaluation and analysis. Thequantification may include, but is not limited to, volume, thickness,area and the like. The quantified results may be used to automaticallyor manually select the optimal start point and stop point of a veneeringtreatment. In addition, the ability to visualize the quantified resultsprovides a reference for a doctor or patient to select the preferableveneering option. For example, as illustrated in the graph of FIG. 20,the doctor and patient can determine the optimal start and stop point,which yields the least amount of tooth mass removal and/or mass build-upover a given amount of available treatment time. Optimality alsoincludes the probability of achieving the Final alignment position for agiven type of malocclusion in the available treatment time. It should beunderstood that available treatment time equates to an amount of toothmovement that may be realized during the available treatment time.

FIG. 21 is a flowchart illustrating a process s2100 for simulating thecreation of veneers using orthodontic and prosthodontic techniques.FIGS. 22A and 22B are simplified views of a dental arch in an Initialposition and in a Final alignment position, respectively.

Referring to FIGS. 21, 22A and 22B, in step s2102, the dentalprofessional, perhaps in conjunction with a dental laboratory, maycreate a computer-generated, 3-D, virtual model of the patient's actualdentition in a beginning configuration 2202 (FIG. 22A). The virtualmodel may be generated prior to any tooth preparation, so that the modelrepresents the patient's dentition in a pretreatment state. Someprocesses for making such a virtual model are described in, for example,the '207 publication and the '749 application previously incorporatedherein by reference.

The dental professional as shown in step s2104, again perhaps inconjunction with the dental laboratory or any other company orservice/product provider, may transform the virtual model of thebeginning configuration. The dental professional may use virtualorthodontia to create a computer-generated, 3-D, virtual model of thepatient's dentition in a Final alignment position or Final configuration2204 (FIG. 22B), which represents the desired “smile” or design goalthat the patient and doctor desire. The virtual orthodontia may includemanipulation and movement of teeth in the virtual model. The orthodontictreatment may also include the modeling of several intermediate stagesbetween the beginning configuration and Final alignment position. Thebeginning configuration or else one of the intermediate stages may beconsidered an Initial position for starting the veneering treatment aswill be explained below.

In step s2108, a tentative restoration volume (simulated veneer) may becalculated for a given time available for treatment. FIG. 23 illustratesan embodiment for calculating the tentative restoration volume of steps2108.

Referring now to FIG. 23, one embodiment of the present methods maybegin when a patient first consults a dental professional regarding anorthodontic procedure and/or a prosthodontic procedure (s2302). Duringthe initial consultation, the dental professional and the patient maydiscuss the patient's treatment goal(s) and any constraints that mightlimit the time available for treatment. For example, the patient maydesire to have his or her smile enhanced, but has only a six-monthwindow of opportunity for treatment. In this situation, the timeframefor treatment is limited, and an appropriate orthodontic/prosthodontictreatment plan must be set to fit within the timeframe.

In the present embodiment, the dental professional may decide thatsubstantially the entire six-month window of treatment time be used toprovide a particular amount of tooth movement before starting theveneering treatment. Accordingly, in step s2304, the dentalprofessional, again perhaps in conjunction with the dental laboratory orany other company or service/product provider, simulates orthodonticmovement of the teeth between the beginning configuration and anIntermediate position.

In the present embodiment, the Intermediate position represents thestarting point or the Initial position for the veneering treatment andis so specified (s2306). Now that the dental professional knows thepredicted Initial position of the teeth, the dental professional maydetermine the Prepared position.

In step s2308, the dental professional, again perhaps in conjunctionwith the dental laboratory or any other company or service/productprovider, may transform the virtual model of the Initial position usingvirtual prosthodontia to create a computer-generated, 3-D, virtual modelof the patient's dentition in a Prepared or cut configuration. Thevirtual prosthodontics may include the tooth mass removal that thedental professional deems necessary to achieve the design goal (thedesired “smile”). The initial Prepared position is referred tohereinafter as the tentative Prepared position.

In step s2308, the dental professional may quantify the amount of toothmass to be removed from the dentition to achieve the desired smile.Referring to FIG. 24, in one embodiment, Intermediate tooth 2402 andPrepared tooth 2404 are superimposed to determine Prepared region 2406,which is the difference in volume between Intermediate tooth 2402 andPrepared tooth 2404. Prepared region 2406 represents the amount of toothstructure to be removed (V_(r)).

Referring again to FIG. 23, in step s2310, the dental professional maysuperimpose the teeth in the Intermediate position with the teeth in theFinal alignment position to define a sweep path from the Intermediateposition to the Final alignment position for each tooth to be veneered.For example, FIG. 25 is a side view and top view of Prepared tooth 2404where the swept volume V_(s) is shown. In this embodiment, swept volumeV_(s) is the space occupied by moving a geometric model of Preparedtooth 2404 along a path from the Intermediate position to the Finalalignment position.

Reference is made to the swept volume in the embodiments described,however, one of ordinary skill in the art will understand that manywell-known numerical algorithms exist that may be used to generate theenvelope model of the Intermediate position and the Final alignmentposition. For example, such algorithms are referred to as the marchingcube, convex hull, maxima, and Boolean union operations. In addition,the swept volume may be estimated analytically.

In step s2312, simulated veneers are generated as separate geometricmodels apart from the Prepared tooth.

In step s2314, the simulated veneer may be evaluated by reviewing thequantified measurements and visualizing the final geometry of thesimulated veneers. For example, Preparation region 2406 is calculatedwhich represents the amount of tooth structure to be removed inpreparing the teeth. Also, the total restoration volume is calculated bysubtracting the Prepared tooth volume from the sweep volume to createthe total restoration volume. The simulated veneers may be visualized tofacilitate any shape modification, color modification or any othermodification that the dental professional deems appropriate.

Referring again to FIG. 21, once a tentative restoration volume has beencalculated (s2108), a decision is made in step s2110 as to whether therestoration volume is acceptable to the dental professional and/or thepatient. In some cases, for example, the dental professional or patientmay decide that the restoration volume is too large or that the amountof tooth structure required to be removed is too great. In these cases,the process may return to the orthodontic simulation step s2104 wherethe dental professional attempts to modify the design goal, which mayinclude manipulating the movement of the teeth to lessen the concerns ofthe dental professional and patient.

In cases where the tentative restoration is acceptable, the processcontinues to step s2112, where a check is made to determine if the sweptvolume may need to be modified to assure that the sweep volume of thetooth does not overlap the swept volume of a neighboring tooth orveneer.

In step s2114, if overlap does exist, the overlap needs to be resolved.One approach to remove the overlap is to deform or locally modify theoverlap area of the veneer model.

In step s2116, if there is no overlap, the tentative restoration isdeemed to be the final restoration and may be subsequently made into anactual restoration.

Referring now to FIG. 26, as shown in step s2602, to create an actualrestoration from the final restoration, a veneer template may beselected from a veneer library, which includes all types, shapes andsizes of veneers. The veneer template provides a reference geometry forthe modeling of the actual restoration. The reference geometry of theveneer template may be a 3D digital model. Generally, the veneertemplate may be defined by various physical parameters, such as height,width, thickness and the like.

As shown in step s2604, after a veneer template has been selected, theveneer template may be used to generate the actual veneer shape model(actual restoration) by deforming the veneer template to approximate thefinal restoration model. When the physical parameters of the veneertemplate are changed, the geometry of the actual restoration changes.The deformation may be achieved through the adjustment of the physicalparameters, 3D morphing and the adjustment of the control points on thetemplate surface.

As shown in step s2606, after the actual veneer shape model isgenerated, if necessary, the actual veneer shape model may be furtherlocally modified automatically or interactively to satisfy any clinicalrequirements and user preferences.

Once the actual veneer shape model, with any modifications, has beengenerated, it may be made into a physical veneer. In one embodiment, thephysical veneer may be created by creating the reverse veneer with atemplate, filling the template with a dental material, such as acrylic,composite, silicone, and the like, in the uncured state and then curingthe dental material, creating the physical veneer in the desired shape.In one alternative embodiment, the physical veneer may be built updirectly in wax with a 3-D printer. The wax may then be invested andcast into, for example, porcelain or glass, using the lost-waxtechnique. In another alternative embodiment, the physical veneer may beconverted directly into a CAD-CAM object that may be milled from a blockof porcelain or glass.

The following points may be considered aspects of the presentdisclosure:

Point 1. A method for developing a dental treatment plan comprising: (a)creating a virtual model of a dental patient's dentition in a beginningconfiguration, the dentition including teeth; (b) transforming thevirtual model of the dentition using virtual orthodontics from thebeginning configuration into an intermediate configuration; (c)transforming the virtual model of the dentition using virtualprosthodontics from the intermediate configuration into a finalconfiguration, the final configuration including the teeth and a dentalrestoration; (d) transforming the dentition from the beginningconfiguration into the intermediate configuration; (e) performing atleast one of tooth surface removal, tooth cutting and tooth reshaping onthe dentition; and (f) affixing the dental restoration to the dentition.

Point 2. The method of point 1, further comprising: g) identifying andevaluating a restorative parameter.

Point 3. The method of point 2, further comprising iterating steps b),c) and g).

Point 4. The method of point 2, wherein the restorative parameter is avolume of tooth material to be removed, an aesthetic feature, or aconfiguration of interior portions of the dentition

Point 5. The method of point 2, further comprising: h) determiningwhether the restorative parameter meets a desired threshold.

Point 6. The method of point 5, further comprising creating anorthodontic plan based upon the beginning configuration, theintermediate configuration and the final configuration.

Point 7. The method of point 6, further comprising creating anorthodontic appliance based upon the orthodontic plan.

Point 8. The method of point 1, further comprising creating arestorative goal based upon the beginning configuration, theintermediate configuration and the final configuration.

Point 9. The method of point 8, further comprising creating aprosthodontic preparation based upon the restorative plan.

Point 10. The method of point 1, wherein transforming the actualdentition from the beginning configuration into the intermediateconfiguration comprises the use of at least one dental aligner.

Point 11. The method of point 1, further comprising verifying theefficacy of the at least one of tooth surface removal, tooth cutting andtooth reshaping.

Point 12. The method of point 11, wherein verifying comprisespositioning a preparation guide over the dentition and measuring aclearance between a tooth and the preparation guide.

Point 13. The method of point 12, wherein the preparation guide issubstantially congruent to the final configuration of the dentition.

Point 14. The method of point 12, wherein the preparation guide includesat least one aperture that enables a portion of the tooth to protrudebeyond a wall portion of the preparation guide.

Point 15. The method of point 11, wherein verifying comprisespositioning the dental restoration on the dentition and verifying aproper fit.

Point 16. The method of point 15, further comprising repeating step e)when the dental restoration does not fit properly on the dentition.

Point 17. A method for preparing a dental treatment plan comprising:creating a virtual model of a dental patient's dentition, the dentitionincluding teeth; transforming the virtual model of the dentition usingvirtual prosthodontics to yield a desired outcome relative to at leastone restorative parameter; iterating on the transforming step untilsubstantially achieving the desired outcome relative to the at least onerestorative parameter; and generating a prosthodontic treatment planbased upon the substantially achieved treatment goal.

Point 18. The method of point 17, wherein the at least one restorativeparameter comprises a volume of tooth material to be removed, anaesthetic feature, a configuration of interior portions of thedentition, or a combination thereof.

Point 19. The method of point 17, wherein iterating on the transformingstep comprises: transforming the virtual model of the dentition usingvirtual orthodontics to facilitate substantially achieving the desiredoutcome relative to the at least one restorative parameter.

Point 20. A preparation guide for use during a prosthodontic procedure,comprising: a virtually generated overlay configured to cover at least aportion of teeth in a patient's upper or lower arch, the overlayincluding a wall portion forming at least one cavity configured toreceive the teeth; wherein the wall portion includes at least oneaperture configured to receive a protruding portion of the teeth.

Point 21. The preparation guide of point 20, wherein the virtual overlayis configured to cover all teeth in a patient's upper or lower arch.

Point 22. A method of fabricating a preparation guide for use during aprosthodontic procedure comprising: creating a first virtual model of apatient's dentition in a beginning configuration; manipulating thevirtual model using computer software to create a second virtual modelof the patient's dentition in a desired final configuration;superimposing the first and second virtual models; identifying, in thesuperimposed models, intersection boundaries at areas where thedentition of the first model protrudes beyond the dentition of thesecond model; and fabricating the preparation guide to substantiallyconform to the second model and having apertures defined by theintersection boundaries.

Point 23. The method of point 22, further comprising the step ofreviewing the second virtual model with the patient.

Point 24. The method of point 23, further comprising the step ofmanipulating the second virtual model to arrive at an alternate desiredfinal configuration.

Point 25. A method for developing a dental treatment plan, the methodcomprising: (a) creating a virtual model of a dental patient's dentitionin a beginning configuration, the dentition including teeth; (b)identifying at least one parameter of the dental treatment program to becontrolled so that the parameter falls within a desired range; (c)transforming the virtual model of the dentition using at least one ofvirtual orthodontics and virtual prosthodontics from the beginningconfiguration into a final configuration; (d) evaluating the effect ofthe transforming step on the parameter; and (f) repeating steps b), c)and d) until the transforming step produces a desired effect on theparameter.

Point 26. The method of point 25, wherein identifying at least oneparameter of the dental treatment program to be controlled so that theparameter falls within a desired range comprises identifying a pluralityof parameters of the dental treatment program to be controlled so thatthe plurality of parameters fall within desired ranges.

Point 27. A method for generating dental information of a patientcomprising: creating a virtual model of a patient's dentition in a firstconfiguration, the dentition including at least one tooth having areference volume; generating a model volume created as the at least onetooth travels from the first configuration to a second configuration;and subtracting the reference volume from the model volume to yield abuild-up volume.

Point 28. The method of point 27, further comprising creating a virtualmodel of a patient's dentition in a prepared configuration.

Point 29. The method of point 28, further comprising determining aremoved volume by subtracting a volume of the dentition in the preparedconfiguration from the reference volume.

Point 30. The method of point 29, further comprising determining arestoration volume by combining the removed volume and the build-upvolume.

Point 31. The method of point 28, further comprising: transforming thevirtual model of the patient's dentition from the first configurationinto a first intermediate configuration; generating a first intermediatemodel volume created as the at least one tooth travels from the firstintermediate configuration to the second configuration; subtracting thereference volume from the first intermediate model volume to yield afirst intermediate build-up volume; and evaluating the effect of thetransforming step on the first intermediate build-up volume to determineif the effect is a desired effect.

Point 32. The method of point 31, further comprising: determining aremoved volume by subtracting a volume of the dentition in the preparedconfiguration from the reference volume; and determining a restorationvolume by combining the removed volume and the first intermediatebuild-up volume.

Point 33. The method of point 31, further comprising: transforming thevirtual model of the patient's dentition from the first configurationinto a second intermediate configuration; generating a secondintermediate model volume created as the at least one tooth travels fromthe second intermediate configuration to the second configuration;subtracting the reference volume from the second intermediate modelvolume to yield a second intermediate build-up volume; and evaluatingthe effect of the transforming step on the second intermediate build-upvolume to determine if the effect is a desired effect.

Point 34. The method of point 33, further comprising: determining aremoved volume by subtracting a volume of the dentition in the preparedconfiguration from the reference volume; and determining a restorationvolume by combining the removed volume and the second intermediatebuild-up volume.

Point 35. The method of point 27, wherein generating the model volumecomprises: determining the volume of the virtual space occupied by theat least one tooth as the at least one tooth travels from the firstconfiguration to the second configuration.

Point 36. The method of point 27, further comprising: verifying whetherthe build-up volume overlaps a neighboring virtual tooth volume orvirtual veneer volume.

Point 37. The method of point 36, further comprising: deforming thebuild-up volume to resolve the overlap.

Point 38. The method of point 27, wherein creating the virtual model ofa patient's dentition comprises generating a reference contour meshcrown representing the surface boundary of the at least one tooth.

Point 39. The method of point 38, wherein generating the model volumecomprises: calculating the virtual space occupied by the referencecontour mesh crown as the reference contour mesh crown travels from thefirst configuration to the second configuration.

Point 40. A system for generating dental information of a patientcomprising a processor configured to: create a virtual model of apatient's dentition in a first configuration, the dentition including atleast one tooth having a reference volume; generate a model volumecreated as the at least one tooth travels from the first configurationto a second configuration; and subtract the reference volume from themodel volume to yield a build-up volume.

Point 41. The system of point 40, wherein the processor is furtherconfigured to create a virtual model of a patient's dentition in aprepared configuration.

Point 42. The system of point 41, wherein the processor is furtherconfigured to determine a removed volume by subtracting a volume of thedentition in the prepared configuration from the reference volume.

Point 43. The system of point 42, wherein the processor is furtherconfigured to determine a restoration volume by adding the removedvolume and the build-up volume.

Point 44. The system of point 40, wherein the processor is furtherconfigured to: transform the virtual model of the patient's dentitionfrom the first configuration into a first intermediate configuration;generate a first intermediate model volume created as the at least onetooth travels from the first intermediate configuration to the secondconfiguration; subtract the reference volume from the first intermediatemodel volume to yield a first intermediate build-up volume; and evaluatethe effect of the transform step on the first intermediate buildupvolume to determine if the effect is a desired effect.

Point 45. The system of point 44, wherein the processor is furtherconfigured to: transform the virtual model of the patient's dentitionfrom the first configuration into a second intermediate configuration;generate a second intermediate model volume created as the at least onetooth travels from the second intermediate configuration to the secondconfiguration; subtract the reference volume from the secondintermediate model volume to yield a second intermediate build-upvolume; and evaluate the effect of the transform step on the secondintermediate build-up volume to determine if the effect is a desiredeffect.

Point 46. The system of point 40, wherein the processor is furtherconfigured to: verify whether the build-up volume overlaps a neighboringvirtual tooth volume or virtual veneer volume.

Point 47. The system of point 46, wherein the processor is furtherconfigured to: deform the build-up volume to resolve the overlap.

Point 48. The system of point 40, further comprising a mechanism fordisplaying a virtual representation of the first configuration, thebuild-up volume, the restoration volume, the removed volume, the secondconfiguration, the final configuration, the prepared configuration orthe reference volume.

The flowcharts provided herein illustrate example embodiments of thepresent methods. In some alternative embodiments, the steps shown in oneor more figures may occur out of the order presented. For example, insome cases, two steps shown in succession may be executed substantiallyconcurrently, or the steps may sometimes be executed in the reverseorder. Those of ordinary skill in the art will also appreciate that thescope of the present methods is defined only by the claims providedbelow, and therefore some embodiments may not include all of the stepsshown in the figures.

The above description presents the best mode contemplated for carryingout the present prosthodontic and orthodontic apparatus and methods, andof the manner and process of making and using them, in such full, clear,concise, and exact terms as to enable any person skilled in the art towhich it pertains to make these apparatus and use these methods. Theseapparatus and methods are, however, susceptible to modifications andalternate constructions from those discussed above that are equivalent.Consequently, these apparatus and methods are not limited to theparticular embodiments disclosed. On the contrary, these apparatus andmethods cover all modifications and alternate constructions comingwithin the spirit and scope of the apparatus and methods as generallyexpressed by the following claims, which particularly point out anddistinctly claim the subject matter of the apparatus and methods.

What is claimed is:
 1. A method of planning a dental treatment for apatient's dentition, the method comprising: receiving a virtual model ofthe patient's dentition; receiving a constraint on a restorativeparameter for the dental treatment; generating a prosthodontic treatmentplan based on the virtual model of the patient's dentition; generatingan orthodontic treatment plan based on the virtual model of thepatient's dentition, the orthodontic treatment plan including aplurality of tooth movement steps to move one or more teeth of thepatient's dentition from a beginning configuration to a plurality ofintermediate configurations; evaluating the restorative parameter ateach of the plurality of intermediate configurations; setting a first ofthe plurality of intermediate configurations to begin prosthodontictreatment, the first of the plurality of intermediate configurationssatisfying the constraint on the restorative parameter; and fabricatingat least one of: a series of orthodontic aligners based on theorthodontic treatment plan from the beginning configuration to the firstof the plurality of intermediate configurations, and a preparation guideaccording to the prosthodontic treatment plan.
 2. The method of claim 1,wherein the restorative parameter comprises a time for performing thedental treatment, and wherein the orthodontic treatment plan is modifiedaccording to a constraint on the time for the dental treatment.
 3. Themethod of claim 2, wherein the constraint on the time for the dentaltreatment is a maximum time.
 4. The method of claim 1, wherein therestorative parameter comprises an amount of tooth structure removal,and wherein the orthodontic treatment plan is modified according to aconstraint on the amount of tooth structure removed.
 5. The method ofclaim 4, wherein the constraint on the amount of tooth structure removedis a maximum amount of tooth structural removed.
 6. The method of claim1, wherein the restorative parameter comprises a veneer thickness, andwherein the orthodontic treatment plan is modified according to aconstraint on the veneer thickness.
 7. The method of claim 6, whereinthe constraint on the veneer thickness is a minimum veneer thickness. 8.The method of claim 1, wherein the restorative parameter comprises alingual alignment, and wherein the orthodontic treatment plan ismodified according to a constraint on the lingual alignment.
 9. Themethod of claim 1, wherein evaluating the restorative parameter at eachof the plurality of intermediate configurations includes virtuallyiterating preparation specifications for the prosthodontic treatmentplan based on the plurality of intermediate configurations.
 10. Themethod of claim 9, wherein virtually iterating preparationspecifications includes determining a volume of tooth material removed.11. A non-transitory computer readable medium comprising instructionsfor planning a dental treatment for a patient's dentition that whenexecuted by a processor cause a computer to: receive a virtual model ofthe patient's dentition; receive a constraint on a restorative parameterfor the dental treatment; generate a prosthodontic treatment plan basedon the virtual model of the patient's dentition; generate an orthodontictreatment plan based on the virtual model of the patient's dentition,the orthodontic treatment plan including a plurality of tooth movementsteps to move one or more teeth of the patient's dentition from abeginning configuration to a plurality of intermediate configurations;evaluate the restorative parameter at each of the plurality ofintermediate configurations; and set a first of the plurality ofintermediate configurations to begin prosthodontic treatment, the firstof the plurality of intermediate configurations satisfying theconstraint on the restorative parameter; and cause a fabrication machineto fabricate at least one of: a series of orthodontic aligners based onthe orthodontic treatment plan from the beginning configuration to thefirst of the plurality of intermediate configurations, and a preparationguide according to the prosthodontic treatment plan.
 12. Thenon-transitory computer readable medium of claim 11, wherein therestorative parameter comprises a time for performing the dentaltreatment, and wherein the orthodontic treatment plan is modifiedaccording to a constraint on the time for the dental treatment.
 13. Thenon-transitory computer readable medium of claim 12, wherein theconstraint on the time for the dental treatment is a maximum time. 14.The non-transitory computer readable medium of claim 11, wherein therestorative parameter comprises an amount of tooth structure removed,and wherein the orthodontic treatment plan is modified according to aconstraint on the amount of tooth structure removed.
 15. Thenon-transitory computer readable medium of claim 14, wherein theconstraint on the amount of tooth structure removed is a maximum amountof tooth structural removed.
 16. The non-transitory computer readablemedium of claim 11, wherein the restorative parameter comprises a veneerthickness, and wherein the orthodontic treatment plan is modifiedaccording to a constraint on the veneer thickness.
 17. Thenon-transitory computer readable medium of claim 16, wherein theconstraint on the veneer thickness is a minimum veneer thickness. 18.The non-transitory computer readable medium of claim 11, wherein therestorative parameter comprises a lingual alignment, and wherein theorthodontic treatment plan is modified according to a constraint on thelingual alignment.
 19. The non-transitory computer readable medium ofclaim 11, wherein the instructions that cause the computer to evaluatethe restorative parameter at each of the plurality of intermediateconfigurations include instructions to cause the computer to virtuallyiterate preparation specifications for the prosthodontic treatment planbased on the plurality of intermediate configurations.
 20. Thenon-transitory computer readable medium of claim 19, wherein theinstructions that cause the computer to virtually iterate preparationspecifications include instructions to cause the computer to determine avolume of tooth material removed.